The engine immobiliser system is designed to prevent the vehicle from being stolen. This system uses a transponder key ecu that stores the key codes of authorized ignition keys. If an attempt is made to start the engine using an unauthorized key, the ecu sends a signal to the ecm to prohibit fuel delivery and ignition, effectively disabling the engine.

The transponder key coil receives this signal, the transponder key amplifier amplifies it, and then the signal is transmitted to the ecu. The ecu matches the key's id code with the vehicle's id code, which was previously registered in the ecu and then communicates the results to the ecm using sfi communication.
Engine immobiliser system
How to proceed with troubleshootingRegistration
In case of tire pressure warning ecu
replacement
Read id stored in the old ecu using the intelligent
tester.
In case of tire pressure warning valve and
transmitter and/or tire pressure warning
ecu replacement
Read the id written on the tire pressure monitor
valve.
...
Driver side - side airbag sensor assembly initialization incomplete
Description
The side airbag sensor lh consists of part including the diagnostic circuit
and the lateral deceleration
sensor.
When the center airbag sensor receives signals from the lateral deceleration
sensor, it determines
whether or not the srs should be activated.
Dtc b1623/81, b ...
Vsc warning light remains on
Description
The skid control ecu is connected to the combination meter via the can
communication system.
W/o multi information display:
if the skid control ecu stores any dtcs which relate to the vsc system, the vsc
warning light comes on
in the combination meter.
W/ multi information d ...